单项选择题
A preson who sees someone fall overboard should（）.
A.call for help and keep the individual in sight B.run to the radio room to send an emergency message C.immediately jump in the water to assist the individual D.go to the bridge for the
单项选择题 A portable dry chemical fire extinguisher discharges by（）.
单项选择题 A portable foam (stored-pressure type) fire extinguisher would be most useful in combating a fire in（）.
单项选择题 A position obtained by applying only your vessel’s coures and speed to a known position is a（）.
